Wireless power transmission has received an increasing interest over the past years with the expanding market of mobile devices, wearable electronics, and wireless sensor nodes. Wireless power transmission has been most widely studied using electromagnetic coupling between two coils, referred as inductive wireless power transmission. In this approach, a transmitter coil produces an alternating magnetic field that directly induces a voltage and current in a receiver coil placed at some distance away. In certain embodiments of inductive wireless power transmission, electrical resonance is used in the transmitter coil and/or receiver coil.